AIM: The fentanyl transdermal patch (Duro-gesic® D-TRANS) is a strong pain medication for moderate to severe chronic pain that can provide long-lasting relief for persistent pain. This study was conducted to determine the analgesia and adverse effects of the fentanyl transdermal patch (Durogesic® D-TRANS) postelective laparotomy.METHODS: One-hundred twenty patients undergoing elective laparotomy were randomized into two groups of fentanyl and placebo. In the first group, patients received two fentanyl patches with 25 and 50 µg in 10 hours preoperatively. Patient’s postoperative assessments included pain score, adverse effects, mean amount and interval of supplementary morphine, respiratory rate and oxygen saturation, which were recorded during 36 hours.RESULTS: The mean pain intensity scores over 36 hours in fentanyl transdermal patch durogesic (FTD) group were significantly less than placebo group (FTD, 35.28; placebo, 46.61 and P=0.01). However, the pain score at the 3rd timepoint in the placebo group was slightly less than the FTD group (39.4±2.23 vs. 39.47±4.97, respectively). The mean interval and amount of supplementary morphine were significantly better in the FTD group than the placebo group (FTD 367.7±349.7 min vs. placebo 59±13.88 min; P=0.04 and FTD 2.10±3.46 mg vs. 29.15±3.71 mg; P<0.001, respectively). The incidence of adverse effects including vomiting (FTD 16 vs. placebo 9; P=0.45), nausea (FTD 22 vs. placebo 18; P=0.33), itching (FTD 16 vs. placebo 18; P=1.00) and respiratory depression (FTD 1 vs. placebo 0; P=1.00) were not significant between the groups, except the dizziness that had a higher incidence in the FTD group (FTD 23 vs. placebo 1; P=0.02).CONCLUSION: It seems that the fentanyl transdermal patch system is a safe and effective procedure to use in post laparotomy analgesia and its related adverse effects are not serious.